The crew watched the disaster unfold, mouths slack in awe. The Atlantic impactor had been the biggest single chunk of the comet, but it had been as precisely targeted as the rest. It had come down in the middle of the ocean, on a ridge of continental-crust formation about a thousand kilometres south of a small island called Iceland. From viewpoints on the ground, a particle of light was seen to descend from the sky, touching the water, and then, behind a wall of boiling cloud, a pencil of light shot vertically to the sky. From space, as rings of cloud expanded, a fireball blossomed, clinging to the carcass of the planet like a boil. The cloud rings merged to become a solid torus, centred on the fireball, and then more clouds formed at higher level. A shock wave spread out through the cloud layer, a reflection of a ring of waves spreading out across the ocean, a water ripple dragging a wall of cloud with it. The ripple in the ocean emerged into clear air.
